Extension of fusions to the pelvis in idiopathic scoliosis

Surgical site infection is a major risk factor of pseudarthrosis in adult spinal deformity surgery

BACKGROUND CONTEXT

Despite the evidence in appendicular skeletal surgery, the effect of infection on spinal fusion remains unclear, particularly after Adult Spinal Deformity (ASD) surgery.

PURPOSE

The purpose of this study was to determine the impact of surgical site infection (SSI) in ASD surgery fusion rates and its association with other risks factors of pseudarthrosis.

STUDY DESIGN

We conducted an international multicenter retrospective study on a prospective cohort of patients operated for spinal deformity.

PATIENT SAMPLE

A total of 956 patients were included (762 females and 194 males).

OUTCOME MEASURES

Patient's preoperative characteristics, pre and postoperative spinopelvic parameters, surgical variables, postoperative complications and were recorded. Surgical site infections were asserted in case of clinical signs associated with positive surgical samples. Each case was treated with surgical reintervention for debridement and irrigation. Presence of pseudarthrosis was defined by the association of clinical symptoms and radiological signs of nonfusion (either direct evidence on CT-scan or indirect radiographic clues such as screw loosening, rod breakage, screw pull out or loss of correction). Each iterative surgical intervention was collected.

METHODS

Univariate and multivariate analysis with logistic regression models were performed to evaluate the role of risk factors of pseudarthrosis.

RESULTS

Nine hundred fifty-six surgical ASD patients with more than two years of follow-up were included in the study. 65 of these patients were treated for SSI (6.8%), 138 for pseudarthrosis (14.4%), and 28 patients for both SSI and pseudarthrosis. On multivariate analysis, SSI was found to be a major risk factor of pseudarthrosis (OR=4.4; 95% CI=2.4,7.9) as well as other known risks factors: BMI (OR=1.1; 95% CI=1.0,1.1), smoking (OR=1.6; 95% CI=1.1,2.9), performance of Smith-Petersen osteotomy (OR = 1.6; 95% CI 1.0,2.6), number of vertebrae instrumented (OR=1.1; 95% CI=1.1,1.2) and the caudal level of fusion, with a distal exponential increment of the risk (OR max for S1=6, 95% CI=1.9,18.6).

CONCLUSION

SSI significantly increases the risk of pseudarthrosis with an OR of 4.4.

Pelvic obliquity associated with neuromuscular scoliosis in cerebral palsy: cause and treatment

STUDY DESIGN

Literature Review.

OBJECTIVE

Review the etiology, clinical manifestations, diagnosis, and treatment of pelvic obliquity in cerebral palsy patients with neuromuscular scoliosis. Neuromuscular scoliosis (NMS) in cerebral palsy (CP) patients is rapidly progressive and often leads to an imbalance in musculoskeletal mechanics that extends to the pelvis. A horizontal misalignment of the pelvis in the frontal plane known as pelvic obliquity (PO) is a common finding in this population. When untreated, PO can exacerbate the back pain, postural strain, and walking difficulties experienced by these patients. Establishing the manifestation and treatment plan for PO in the setting of NMS can provide valuable insight for diagnosis and management.

METHODS

A comprehensive literature review was performed on the etiology, clinical manifestations, diagnosis, and treatment of pelvic obliquity in the setting of NMS in CP. The advantages and limitations of measurement and treatment options were evaluated.

RESULTS

PO is categorized into suprapelvic, infrapelvic, and intrapelvic causes, each presenting with a unique pattern of pathology. NMS in CP with hip contractures and structural deformities fall into these categories. The Maloney and O'Brien methods of pelvic measurement have demonstrated superior utility and are recommended for clinical diagnosis. The management of PO in NMS patients is focused on the cause of malalignment, with posterior fusion, contracture release, and osteotomy encompassing the mainstay of treatment.

CONCLUSION

PO is commonly found in patients with NMS in cerebral palsy. There is currently no standard method for determining the PO angle. Interventions designed to reduce scoliotic curves and release tissue contractures can level the pelvis and restore proper alignment of the spine and sacrum in the coronal plane in these patients. Further understanding of the causes of PO in NMS, as well as the establishment of a standardized measuring technique and diagnostic parameters will allow for more effective treatment options and improve outcomes in patients with CP.

LEVEL OF EVIDENCE

N/A.

Percutaneous and open iliac screw safety and accuracy using a tactile technique with adjunctive anteroposterior fluoroscopy

BACKGROUND CONTEXT

All currently described percutaneous iliac screw placement methods are entirely dependent on fluoroscopy.

PURPOSE

The purpose of this study was to determine the safety and the accuracy of percutaneous and open iliac screw placement using a primarily tactile technique with adjunctive anteroposterior (AP) fluoroscopy.

STUDY DESIGN/CONTEXT

All patients who underwent open and percutaneous iliac screw placement over a 5-year period were identified. Charts were reviewed to assess for any instances of neurologic or vascular injury associated with iliac screw placement. Screw accuracy was judged with postoperative computed tomography (CT) scans.

PATIENT SAMPLE

A total of 133 patients were identified who underwent open or percutaneous iliac screw placement. Computed tomography scans were available for 57 patients, and all of these patients were included in the study, with a total of 115 iliac screws.

OUTCOME MEASURES

Radiographic measurements were performed, consisting of the distance of the iliac screw to the sciatic notch on postoperative radiographs and CT scans. Computed tomography scans were used to determine iliac screw accuracy.

METHODS

Charts were reviewed to assess for any neurologic or vascular injuries related to screw placement. The distance of the iliac screw to the sciatic notch was measured and compared on AP radiography and CT scans. Computed tomography scans were assessed for any screw violation of the iliac cortex or the sciatic notch. The accuracy of open iliac screw placement was compared with minimally invasive percutaneous placement.

RESULTS

There were no neurologic or vascular injuries related to screw placement in the 133 patients. Computed tomography scans were available for 115 iliac screws, with 3 cortical breaches, all by less than 2 mm. All 112 other screws were accurately intraosseous. There was a strong correlation between the iliac screw to the sciatic notch distance when measured by CT scan compared with AP radiography (r=0.9), thus validating the accuracy of AP fluoroscopy in guiding iliac screw placement with respect to the sciatic notch. Iliac screw accuracy was equal with the open and percutaneous insertion techniques.

CONCLUSIONS

The described surgical technique represents a safe and reliable surgical option for iliac screw placement. Intraoperative AP fluoroscopy accurately reflects the distance of the iliac screw to the sciatic notch. Percutaneous iliac screws placed with this technique are as accurate as open iliac screws.

Pseudarthrosis in adult and pediatric spinal deformity surgery: a systematic review of the literature and meta-analysis of incidence, characteristics, and risk factors

We conducted a systematic review with meta-analysis and qualitative synthesis. This study aims to characterize pseudarthrosis after long-segment fusion in spinal deformity by identifying incidence rates by etiology, risk factors for its development, and common features. Pseudarthrosis can be a painful and debilitating complication of spinal fusion that may require reoperation. It is poorly characterized in the setting of spinal deformity. The MEDLINE, EMBASE, and Cochrane databases were searched for clinical research including spinal deformity patients treated with long-segment fusions reporting pseudarthrosis as a complication. Meta-analysis was performed on etiologic subsets of the studies to calculate incidence rates for pseudarthrosis. Qualitative synthesis was performed to identify characteristics of and risk factors for pseudarthrosis. The review found 162 articles reporting outcomes for 16,938 patients which met inclusion criteria. In general, the included studies were of medium to low quality according to recommended reporting standards and study design. Meta-analysis calculated an incidence of 1.4% (95% CI 0.9-1.8%) for pseudarthrosis in adolescent idiopathic scoliosis, 2.2% (95% CI 1.3-3.2%) in neuromuscular scoliosis, and 6.3% (95% CI 4.3-8.2%) in adult spinal deformity. Risk factors for pseudarthrosis include age over 55, construct length greater than 12 segments, smoking, thoracolumbar kyphosis greater than 20°, and fusion to the sacrum. Choice of graft material, pre-operative coronal alignment, post-operative analgesics, and sex have no significant impact on fusion rates. Older patients with greater deformity requiring more extensive instrumentation are at higher risk for pseudarthrosis. Overall incidence of pseudarthrosis requiring reoperation is low in adult populations and very low in adolescent populations.

Effect of Surgical Fusion on Volitional Weight-Shifting in Individuals With Adolescent Idiopathic Scoliosis

STUDY DESIGN

Prospective.

OBJECTIVES

The goals of this study were to (1) evaluate the differences in weightbearing symmetry between individuals with adolescent idiopathic scoliosis (AIS) and typically developing controls; (2) observe the effect of posterior spinal fusion and instrumentation (PSFI) on volitional weight-shifting at 1 and 2 years postoperatively; and (3) evaluate whether lowest instrumented fusion level (ie, lowest instrumented vertebra [LIV]) in PSFI has an effect on volitional weight-shifting.

SUMMARY OF BACKGROUND DATA

Previous studies have conflicting findings with regard to the effect of scoliosis on postural control tasks as well as the effect of surgery. They have also noted an inconsistent effect of PSFI at different LIVs, with more distal LIVs exhibiting greater reductions in postoperative range of motion.

METHODS

The study was designed with an AIS group of 41 patients (8 males and 33 females) with AIS who underwent PSFI, along with a Control Group of 24 age-matched typically developing participants (12 male and 12 female). Both groups performed postural control tasks (static balance and volitional weight-shifting), with the AIS group repeating the tasks at 1 and 2 years postoperatively.

RESULTS

At baseline, the AIS group showed increased weightbearing asymmetry than the Control Group (p = .01). The AIS group showed improvements in volitional weight-shifting at 2 years over baseline (p < .01). There was no effect of LIV on volitional weight-shifting by the second postoperative year.

CONCLUSIONS

Individuals with AIS have greater weightbearing asymmetry but improved volitional weight-shifting over typically developing controls. PSFI improves volitional weight-shifting beyond preoperative baseline but does not differ significantly by LIV.

Predictive parameters for the antecedent development of hip pathology associated with long segment fusions to the pelvis for the treatment of adult spinal deformity

BACKGROUND

The surgical treatment of adult scoliosis frequently involves long segment fusions across the lumbosacral joints that redistribute tremendous amounts of force to the remaining mobile spinal segments as well as to the pelvis and hip joints. Whether or not these forces increase the risk of femoral bone pathology remains unknown. The aim of this study is to determine the correlation between long segment spinal fusions to the pelvis and the antecedent development of degenerative hip pathologies as well as what predictive patient characteristics, if any, correlate with their development.

METHODS

A retrospective chart review of all long segment fusions to the pelvis for adult degenerative deformity operated on by the senior author at the Duke Spine Center from February 2008 to March 2014 was undertaken. Enrolment criteria included all available demographic, surgical, and clinical outcome data as well as pre and postoperative hip pathology assessment. All patients had prospectively collected outcome measures and a minimum 2-year follow-up. Multivariable logistic regression analysis was performed comparing the incidence of preoperative hip pain and antecedent postoperative hip pain as a function of age, gender, body mass index (BMI), and number of spinal levels fused.

RESULTS

In total, 194 patients were enrolled in this study. Of those, 116 patients (60%) reported no hip pain prior to surgery. Eighty-three patients (71.6%) remained hip pain free, whereas 33 patients (28.5%) developed new postoperative hip pain. Age, gender, and BMI were not significant among those who went on to develop hip pain postoperatively (P < 0.0651, 0.3491, and 0.1021, respectively). Of the 78 patients with preoperative hip pain, 20 patients (25.6%) continued to have hip pain postoperatively, whereas 58 patients reported improvement in the hip pain after long segment fusion for correction of their deformity, a 74.4% rate of reduction. Age, gender, and BMI were not significant among those who continued to have hip pain postoperatively (P < 0.4386, 0.4637, and 0.2545, respectively). Number of levels fused was not a significant factor in the development of hip pain in either patient population; patients without preoperative pain who developed pain postoperatively (P < 0.1407) as well as patients with preoperative pain who continued to have pain postoperatively (P < 0.0772).

CONCLUSION

This study demonstrates that long segment lumbosacral fusions are not associated with an increase in postoperative hip pathology. Age, gender, BMI, and levels fused do not correlate with the development of postoperative hip pain. The restoration of spinal alignment with long segment fusions may actually decrease the risk of developing femoral bone pathology and have a protective effect on the hip.

Implications of spinopelvic alignment for the spine surgeon

The relation of the pelvis to the spine has previously been overlooked as a contributor to sagittal balance. However, it is now recognized that spinopelvic alignment is important to maintain an energy-efficient posture in normal and disease states. The pelvis is characterized by an important anatomic landmark, the pelvic incidence (PI). The PI does not change after adolescence, and it directly influences pelvic alignment, including the parameters of pelvic tilt (PT) and sacral slope (SS) (PI = PT 1 SS), overall sagittal spinal balance, and lumbar lordosis. In the setting of an elevated PI, the spineadapts with increased lumbar lordosis. To prevent or limit sagittal imbalance, the spine may also compensate with increased PT or pelvic retroversion to attempt to maintain anupright posture. Abnormal spinopelvic parameters contribute to multiple spinal conditions including isthmic spondylolysis, degenerative spondylolisthesis, deformity, and impact outcome after spinal fusion. Sagittal balance, pelvic incidence, and all spinopelvic parameters are easily and reliably measured on standing, full-spine (lateral) radiographs, and it is essential to accurately assess and measure these sagittal values to understand their potential role in the disease process, and to promote spinopelvic balance at surgery. In this article, we provide a comprehensive review of the literature regarding the implications of abnormal spinopelvic parameters and discuss surgical strategies for correction of sagittal balance. Additionally, the authors rate and critique the quality of the literature cited in a systematic review approach to give the reader an estimate of the veracity of the conclusions reached from these reports.

Adult thoracolumbar and lumbar scoliosis treated with long vertebral fusion to the sacropelvis: a comparison between new hybrid selective spinal fusion versus anterior-posterior spinal instrumentation

BACKGROUND CONTEXT

Combined anteroposterior spinal fusion with instrumentation has been used for many years to treat adult thoracolumbar/lumbar scoliosis. This surgery remains a technical challenge to spine surgeons, and current literature reports high complication rates.

PURPOSE

The purpose of this study is to validate a new hybrid technique (a combination of single-rod anterior instrumentation and a shorter posterior instrumentation to the sacrum) to treat adult thoracolumbar/lumbar scoliosis.

STUDY DESIGN

This study is a retrospective consecutive case series of surgically treated patients with adult lumbar or thoracolumbar scoliosis.

PATIENT SAMPLE

This is a retrospective study of 33 matched pairs of patients with adult scoliosis who underwent two different surgical procedures: a new hybrid technique versus a third-generation anteroposterior spinal fusion.

OUTCOME MEASURES

Preoperative and postoperative outcome measures include self-report measures, physiological measures, and functional measures.

METHODS

In a retrospective case-control study, 33 patients treated with the hybrid technique were matched with 33 patients treated with traditional anteroposterior fusion based on preoperative radiographic parameters. Mean follow-up in the hybrid group was 5.3 years (range, 2-11 years), compared with 4.6 years (range, 2-10 years) in the control group. Operating room (OR) time, estimated blood loss, and levels fused were collected as surrogates for surgical morbidity. Radiographic parameters were collected preoperatively, postoperatively, and at final follow-up. The Scoliosis Research Society Patient Questionnaire (SRS-22r) and Oswestry Disability Index (ODI) scores were collected for clinical outcomes.

RESULTS

Operating room time, EBL, and levels fused were significantly less in the hybrid group compared with the control group (p<.0001). The postoperative thoracic Cobb angle was similar between the hybrid and control techniques (p=.24); however, the hybrid technique showed significant improvement in the thoracolumbar/lumbar curves (p=.004) and the lumbosacral fractional curve (p<.0001). The major complication rate was less in the hybrid group compared with the control group (18% vs. 39%, p=.01). Clinical outcomes at final follow-up were not significantly different based on overall SRS-22r scores and ODI scores.

CONCLUSION

The new hybrid technique demonstrates good long-term results, with less morbidity and fewer complications than traditional anteroposterior surgery select patients with thoracolumbar/lumbar scoliosis. This study received no funding. No potential conflict of interest-associated bias existed.

Rh-BMP-2 for L5-S1 arthrodesis in long fusions to the pelvis for neuromuscular spinal deformity in the pediatric age group: analysis of 11 patients

PURPOSE

Neuromuscular scoliosis is a challenging pathology to treat with high incidence of complications and failure of surgical fusion. Surgical correction can entail long fusion constructs extending to the pelvis. We report our experience in the use of bone morphogenetic protein (BMP) to augment L5-S1 arthrodesis in long segment fusions in pediatric patients with neuromuscular scoliosis.

METHODS

Retrospective review of 11 pediatric patients with neuromuscular spinal deformity (mean, age 13.7 years; range, 10-20 years) who underwent long (mean, 15 levels; range, 10-18 levels) spinal instrumentation and fusion to the pelvis at a single institution from 2007 to 2012 with an average follow-up of 34 months (range, 11-62 months).

RESULTS

Of the 11 patients, one had pseudoarthrosis at L5-S1. The average coronal Cobb angle measured 59° before surgery and 42° immediately after surgery. The average preoperative thoracic kyphosis and lumbar sagittal lordosis measured 34 and 59°, respectively. Immediately after surgery, the thoracic and lumbar angles measured 28 and 39°, respectively. At last follow-up, the average coronal Cobb angle was maintained at 43° and the thoracic and lumbar sagittal angles were 28 and 44°, respectively. An average of 14.2 mg of recombinant human bone morphogenetic protein-2 (rh-BMP-2) was used for each case.

CONCLUSIONS

L5-S1 arthrodesis may be effectively achieved in long fusions for pediatric neuromuscular spinal deformity with posterolateral fusion supplemented with rh-BMP-2. This surgical strategy may be associated with lower complication rates, decreased blood loss, and shorter operative times than circumferential fusion, which is particularly important in this complex fragile patient population.

Multiaxial high-modularity spinopelvis (HMSP) fixation device in neuromuscular scoliosis: a comparative study

PURPOSE

To compare radiological and clinical results in patients operated for neuromuscular scoliosis with pelvic fixation using high-modularity spinopelvic screw (HMSP) designed by authors.

METHODS

Of 54 patients with neuromuscular scoliosis, group 1 comprised of 27 patients with conventional pelvic fixation; and group 2 comprised of 27 patients using HMSP. Results were evaluated radiologically and functionally. We compared preoperative and postoperative complications, especially the loosening or breakage of spinopelvis fixation device, failure of fixation, and the change of shadow around the spinopelvis fixation device.

RESULTS

There was no difference of correctional power, preoperative average Cobb's angle of each group was 79.8 and 75 to postoperative 30.2 and 28.3 (P < 0.05). Pelvic obliquity improved from average 18.3°-8.9° in group I and average 24.3°-12.5° in group II (P < 0.05). However, there was no difference between two groups (P > 0.05). Average blood loss was 2,698 ml in group 1 and 2,414.8 ml in group 2 (P > 0.05). Average operative time was 360 min in group 1 and 332 min in group 2 (P = 0.30). There was no difference found between two groups regarding gait and functional evaluation. On the all cases of group 1 and 2, the change of shadow around the spinopelvis fixation device was observed. There was one case of the fracture of spinopelvis fixation device in group I.

CONCLUSION

There was no difference of Cobb's angle and correctional power between the groups using HMSP when compared with the group using standard spinopelvis fixation device. Therefore, HMSP can be used more effectively in case of neuromuscular scoliosis.

Historical and current trends in colon trauma

The authors discuss the evolution of the evaluation and management of colonic trauma, as well as the debate regarding primary repair versus fecal diversion. Their evidence-based review covers diagnosis, management, surgical approaches, and perioperative care of patients with colon-related trauma. The management of traumatic colon injuries has evolved significantly over the past 50 years; here the authors describe a practical approach to the treatment and management of traumatic injuries to the colon based on the most current research. However, management of traumatic colon injuries remains a challenge and continues to be associated with significant morbidity. Familiarity with the different methods to the approach and management of colonic injuries will allow surgeons to minimize unnecessary complications and mortality.

Anterior Spinal Surgery Involving Variant Vascular Anatomy: A Case Report

STUDY DESIGN

Case report of an anterior approach to the spine in the setting of variant vascular anatomy.

OBJECTIVE

To highlight the importance of evaluating vascular anatomy before anterior lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

A 62-year-old woman with idiopathic scoliosis had thoracolumbar fusion in adolescence and subsequently developed symptomatic sub-adjacent segment breakdown. Vascular complications may be encountered during anterior approaches to the spine. Variation in vascular anatomy may compound the difficulty of an already meticulous dissection.

RESULTS

A patient with idiopathic scoliosis who had thoracolumbar fusion in adolescence and subsequently developed symptomatic sub-adjacent segment breakdown. She underwent a 2-stage posterior/anterior procedure. During the anterior retroperitoneal approach, an anomalous left inferior vena cava was encountered that required tedious dissection for safe and adequate exposure of the lumbar spine.

CONCLUSIONS

When planning anterior lumbar spine surgery, careful review of the vascular anatomy on imaging should be performed. This will help prepare the surgeon for more complex or anomalous anterior anatomy. If atypical vascular anatomy is identified, consideration of a pathologic cause should be investigated.

Selective thoracic fusion in Lenke 1C curves: prevalence and criteria

STUDY DESIGN

Multicenter retrospective analysis of prospectively collected data.

OBJECTIVE

Evaluate radiographical and clinical characteristics of patients undergoing a selective thoracic fusion (STF) for Lenke 1C curves.

SUMMARY OF BACKGROUND DATA

STF of adolescent idiopathic scoliosis has been advocated for the so-called "false double major" curve (Lenke 1C/King type II). Despite these recommendations, many surgeons continue to perform nonselective fusions for this curve type. It is unknown to what extent other factors influence the surgeon's fusion-level selection.

METHODS

A prospective multicenter database included 264 patients with surgically treated Lenke 1C curves and were divided into 2 groups. The STF group included patients with the lowest instrumented vertebra at or cephalad to L1, whereas the nonselective fusion group included patients with the lowest instrumented vertebra at or caudal to L3. Preoperative radiographical, clinical (scoliometer), Scoliosis Appearance Questionnaire (SAQ), and Scoliosis Research Society (SRS) questionnaires were analyzed and compared.

RESULTS

Only 138 of 264 patients (49%) underwent an STF. Sex ratio (90% vs. 86% female), average age (14.7 vs. 14.8 yr), and preoperative main thoracic Cobb angles (56.0° ± 9.9° vs. 55.3° ± 11.4°) were not significantly different (STF vs. nonselective fusion). However, the average thoracolumbar/lumbar (TL/L) preoperative Cobb angle was significantly smaller in the STF group (42.1° ± 8.6° vs. 47.0° ± 9.0°; P < 0.001), whereas the main thoracic: TL/L Cobb ratio (1.35 ± 0.20 vs. 1.18 ± 0.15; P < 0.001), apical vertebral translation, and rotation (1.82 ± 0.59 vs. 1.31 ± 0.53; P < 0.001), (1.16 vs. 0.98; P < 0.001) ratios were significantly greater in the STF group. Preoperative coronal balance, sagittal Cobb angles (including T10-L2 kyphosis) and Risser Grade were not significantly different. Preoperative TL/L scoliometer measures were significantly less in the STF group (8.1° ± 3.7° vs. 10.3° ± 5.4°; P = 0.001). On the SAQ, the STF group had less desire for an appearance change.

CONCLUSION

Despite the recommendation to fuse only the structural thoracic curve in a 1C curve, only 49% of patients were treated with an STF. Those undergoing an STF had smaller TL/L Cobb angles, less TL/L clinical deformity, larger main thoracic: TL/L ratios, and less desire for an appearance change.

LEVEL OF EVIDENCE

3.

Implications of spinopelvic alignment for the spine surgeon

The relation of the pelvis to the spine has previously been overlooked as a contributor to sagittal balance. However, it is now recognized that spinopelvic alignment is important to maintain an energy-efficient posture in normal and disease states. The pelvis is characterized by an important anatomic landmark, the pelvic incidence (PI). The PI does not change after adolescence, and it directly influences pelvic alignment, including the parameters of pelvic tilt (PT) and sacral slope (SS) (PI = PT + SS), [corrected] overall sagittal spinal balance, and lumbar lordosis. In the setting of an elevated PI, the spineadapts with increased lumbar lordosis. To prevent or limit sagittal imbalance, the spine may also compensate with increased PT or pelvic retroversion to attempt to maintain anupright posture. Abnormal spinopelvic parameters contribute to multiple spinal conditions including isthmic spondylolysis, degenerative spondylolisthesis, deformity, and impact outcome after spinal fusion. Sagittal balance, pelvic incidence, and all spinopelvic parameters are easily and reliably measured on standing, full-spine (lateral) radiographs, and it is essential to accurately assess and measure these sagittal values to understand their potential role in the disease process, and to promote spinopelvic balance at surgery. In this article, we provide a comprehensive review of the literature regarding the implications of abnormal spinopelvic parameters and discuss surgical strategies for correction of sagittal balance. Additionally, the authors rate and critique the quality of the literature cited in a systematic review approach to give the reader an estimate of the veracity of the conclusions reached from these reports.

Outcomes and complications of extension of previous long fusion to the sacro-pelvis: is an anterior approach necessary?

BACKGROUND

Patients with previous multilevel spinal fusion may require extension of the fusion to the sacro-pelvis. Our objective was to evaluate the outcomes and complications of these patients, stratified based on whether the revision was performed using a posterior-only spinal fusion (PSF) or combined anterior-posterior spinal fusion (APSF).

METHODS

A retrospective, multicenter evaluation of adults (>18 years old) with a history of prior spinal fusion for scoliosis (≥4 levels) terminating in the distal lumbar spine requiring extension of fusion to the sacro-pelvis (including iliac fixation in all cases), with minimum 2-year follow-up, was performed. Patients were stratified based on approach (APSF vs. PSF) and inclusion of pedicle subtraction osteotomy (PSO). The PSF group included patients treated with an anterior interbody fusion done through a posterior approach, whereas patients in the APSF group all had both anterior and posterior surgical approaches. Clinical outcomes were based on the Scoliosis Research Society (SRS-22) questionnaire.

RESULTS

Between 1995 and 2006, 45 patients (mean age = 49 years) met inclusion criteria, with a mean follow-up of 41.9 months (range 24 to 135 months). Demographic, preoperative, operative, and postoperative radiographic, SRS-22, and follow-up results were similar between APSF (n=30) and PSF (n=15) groups. The APSF group had more complications (13 of 30 vs. 3 of 15) and a greater number of pseudarthrosis (4 of 30 vs. 0 of 15) than the PSF group; however, these differences did not reach statistical significance. Patients treated with a PSO (n=13) had greater sagittal vertical axis correction (7.7 cm vs. 2.2 cm; P=.04) compared with patients not treated with a PSO (n=32). There were no differences in complication rates or follow-up SRS-22 scores based on whether a PSO was performed (P>.05).

CONCLUSIONS

Among adults with previously treated scoliosis requiring extension to the sacro-pelvis, PSF produced radiographic fusion and clinical outcomes equivalent to APSF, whereas complication rates may be lower. PSO resulted in greater sagittal plane correction, without an increase in overall complication rates.

The impact of sagittal balance on clinical results after posterior interbody fusion for patients with degenerative spondylolisthesis: a pilot study

Background

Comparatively little is known about the relation between the sagittal vertical axis and clinical outcome in cases of degenerative lumbar spondylolisthesis. The objective of this study was to determine whether lumbar sagittal balance affects clinical outcomes after posterior interbody fusion. This series suggests that consideration of sagittal balance during posterior interbody fusion for degenerative spondylolisthesis can yield high levels of patient satisfaction and restore spinal balance

Methods

A retrospective study of clinical outcomes and a radiological review was performed on 18 patients with one or two level degenerative spondylolisthesis. Patients were divided into two groups: the patients without improvement in pelvic tilt, postoperatively (Group A; n = 10) and the patients with improvement in pelvic tilt postoperatively (Group B; n = 8). Pre- and postoperative clinical outcome surveys were administered to determine Visual Analogue Pain Scores (VAS) and Oswestry disability index (ODI). In addition, we evaluated full spine radiographic films for pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), thoracic kyphosis (TK), lumbar lordosis (LL), sacrofemoral distance (SFD), and sacro C7 plumb line distance (SC7D)

Results

All 18 patients underwent surgery principally for the relief of radicular leg pain and back pain. In groups A and B, mean preoperative VAS were 6.85 and 6.81, respectively, and these improved to 3.20 and 1.63 at last follow-up. Mean preoperative ODI were 43.2 and 50.4, respectively, and these improved to 23.6 and 18.9 at last follow-up. In spinopelvic parameters, no significant difference was found between preoperative and follow up variables except PT in Group A. However, significant difference was found between the preoperative and follows up values of PT, SS, TK, LL, and SFD/SC7D in Group B. Between parameters of group A and B, there is borderline significance on preoperative PT, preoperative LL and last follow up SS.

Correlation analysis revealed the VAS improvements in Group A were significantly related to postoperative lumbar lordosis (Pearson's coefficient = -0.829; p = 0.003). Similarly, ODI improvements were also associated with postoperative lumbar lordosis (Pearson's coefficient = -0.700; p = 0.024). However, in Group B, VAS and ODI improvements were not found to be related to postoperative lumbar lordosis and to spinopelvic parameters.

Conclusion

In the current series, patients improving PT after fusion were found to achieve good clinical outcomes in degenerative spondylolisthesis. Overall, our findings show that it is important to quantify sagittal spinopelvic parameters and promote sagittal balance when performing lumbar fusion for degenerative spondylolisthesis.

Extension of prior idiopathic scoliosis fusions to the sacrum: a matched cohort analysis of sixty patients with minimum two-year follow-up

STUDY DESIGN

Comparative study.

OBJECTIVE

To compare the radiographic and clinical outcomes of patients undergoing extension of a previous idiopathic scoliosis fusion to the sacrum using either autogenous bone graft or recombinant human bone morphogenetic protein-2 (rhBMP-2).

SUMMARY OF BACKGROUND DATA

Extension of an existing idiopathic scoliosis fusion to the sacrum for distal degeneration or sagittal imbalance has been associated with a high rate of pseudarthrosis. We hypothesized that rhBMP-2 could be successfully used as a substitute for distant autograft in this challenging population.

METHODS

Consecutive patients were identified from a single institution prospective database. The control group (autogenous harvesting without rhBMP-2, 1998-2002) included 24 of 25 patients with minimum 2-year follow-up while the study group (rhBMP-2 without distant autograft, 2002-2006) included 36 of 39 patients with minimum 2-year follow-up. Radiographs were measured using standard adult deformity criteria. Fusions were evaluated by independent observers using a published 4-point scale. Clinical outcomes were evaluated using Scoliosis Research Society and Oswestry Disability Index Questionnaires.

RESULTS

Groups were well matched with respect to demographic, radiographic, and surgical data with the following exceptions: the control group (autogenous graft, no BMP) was younger (43.5 vs. 49.8 years; P = 0.04), had more anterior levels fused (3.3 vs. 1.7; P = 0.01), more thoracoabdominal approaches (25% vs. 2.7%; P = 0.01), and greater estimated blood loss (1938 vs. 1221 mL; P = 0.01). There was 1 wound complication (deep infection) in each group. Rates of radiographic pseudarthrosis (11.1% vs. 20.8%) and revision for pseudarthrosis (5.6% vs. 12.5%) were lower in the rhBMP-2 group, although this did not reach statistical significance. Preoperative, postoperative, and improvements in Scoliosis Research Society and Oswestry Disability Index scores were similar between groups. We did not observe any increase in adverse events with the use of rhBMP-2.

CONCLUSION

BMP-2 is a safe and effective alternative to iliac or rib harvesting when extending an existing idiopathic scoliosis fusion to the sacrum.

Transverse plane pelvic rotation increase (TPPRI) following rotationally corrective instrumentation of adolescent idiopathic scoliosis double curves

Background

We have occasionally observed clinically noticeable postoperative transverse plane pelvic rotation increase (TPPRI) in the direction of direct thoracolumbar/lumbar rotational corrective load applied during posterior instrumentation and arthrodesis for double (Lenke 3 and 6) adolescent idiopathic scoliosis (AIS) curves. Our purposes were to document this occurrence; identify its frequency, associated variables, and natural history; and determine its effect upon patient outcome.

Methods

Transverse plane pelvic rotation (TPPR) can be quantified using the left/right hemipelvis width ratio as measured on standing posterior-anterior scoliosis radiographs. Descriptive statistics were done to determine means and standard deviations. Non-parametric statistical tests were used due to the small sample size and non-normally distributed data. Significance was set at P < 0.05.

Results

Seventeen of 21 (81%) consecutive patients with double curves (7 with Lenke 3 curves and 10 with Lenke 6) instrumented with lumbar pedicle screw anchors to achieve direct rotation had a complete sequence of measurable radiographs. While 10 of these 17 had no postoperative TPPRI, 7 did all in the direction of the rotationally corrective thoracolumbar instrumentation load. Two preoperative variables were associated with postoperative TPPRI: more tilt of the vertebra below the lower instrumented vertebra (-23° ± 3.1° vs. -29° ± 4.6°, P = 0.014) and concurrent anterior thoracolumbar discectomy and arthrodesis (5 of 10 vs. 7 of 7, P = 0.044). Patients with a larger thoracolumbar/lumbar angle of trunk inclination or larger lower instrumented vertebra plus one to sacrum fractional/hemicurve were more likely to have received additional anterior thoracolumbar discectomy and arthrodesis (c = 0.90 and c = 0.833, respectively).

Postoperative TPPRI resolved in 5 of the 7 by intermediate follow-up at 12 months. Patient outcome was not adversely affected by postoperative TPPRI, whether or not it persisted.

Conclusions

Our findings suggest that TPPRI is a decompensation caused by extension of the corrective thoracolumbar rotational load into the lumbosacral hemicurve below. As posterior instrumentation of adolescent idiopathic scoliosis becomes increasingly more effective in the transverse plane, postoperative TPPRI may become more widely noticed. This study provides some assurance that recompensation usually occurs, but that in either event TPPRI does not seem to affect clinical outcome.

Adjacent segment disease after instrumented fusion for idiopathic scoliosis: review of current trends and controversies

STUDY DESIGN

A literature-based review.

OBJECTIVE

To summarize the clinical and morphologic findings leading to diagnosis, the etiologic factors, and principles of management. To identify the strengths and limits of past studies.

SUMMARY OF BACKGROUND DATA

There are considerable controversies regarding etiologic factors, diagnosis, and management of adjacent segment disease in patients instrumented for idiopathic scoliosis.

METHODS

Summarized is past literature and, to some extent, personal experience of the authors.

RESULTS

Several factors participating to this complex pathophysiology are reported. The clinical presentation, occurring after symptom free interval, can vary, and modern morphologic investigations help for diagnosis. Management is often surgical and remains challenging.

CONCLUSIONS

Long-term consequences of spinal fusions are now major concerns, especially in young patients undergoing surgical correction for idiopathic scoliosis. Adjacent segment disease is defined by a combination of clinical symptoms and morphologic findings. Several etiologic factors have been reported, but need to be further studied to prevent and improve the surgical management of this complication.

Spinopelvic parameters in postfusion flatback deformity patients

BACKGROUND CONTEXT

Fixed sagittal imbalance (FSI) may result from loss of adequate lumbar lordosis (LL) after spinal fusion. Pelvic incidence (PI) is a fixed anatomical parameter that determines LL and overall spinal sagittal alignment.

PURPOSE

We describe the spinopelvic parameters in a series of patients with postfusion FSI. We hypothesize that patients who develop postfusion FSI may have a high PI and are thus more at risk from a loss of adequate LL.

STUDY DESIGN

Retrospective chart and image review.

PATIENT SAMPLE

Consecutive patients with degenerative spine disease with clinically significant postoperative FSI after fusion. METHODS/OUTCOME MEASURES: We evaluated 36-in full spine films for PI, LL, pelvic tilt (PT), thoracic kyphosis (TK), and C7 plumb line.

RESULTS

Fifteen patients with clinically significant FSI were identified: 13 women and 2 men (mean age, 63.3 years). They had undergone a mean of 2.9 prior spine surgeries. The mean PI was elevated at 66.7 degrees (normal 48-55 degrees ), mean PT was elevated at 35.5 degrees (normal 12-18 degrees ), mean LL was reduced at 11.8 degrees (normal 43-61 degrees ), mean TK was reduced at 19.3 degrees (normal 41-48 degrees ), and mean C7 plumb line was elevated at 13.1cm (normal <3cm).

CONCLUSIONS

In the current series, patients with FSI after spinal fusion had an elevated PI and inadequate LL. They attempted to compensate for FSI with reduced TK and with increased pelvic retroversion (PT). Overall, it is important to identify sagittal spinopelvic parameters and promote sagittal balance when performing lumbar fusions.

Biomechanical analysis of a disc prosthesis distal to a scoliosis model

STUDY DESIGN

Biomechanical study of bovine spines.

OBJECTIVE

The purpose of this study was to perform a biomechanical test to analyze intervertebral deflections following placement of both 1 and 2 semiconstrained TDRs in the subjacent segments of a long fusion.

SUMMARY OF BACKGROUND DATA

Long-term sequela of long lumbar fusion for scoliosis include adjacent segment disease and flatback syndrome. Total disc replacement (TDR) is a viable option for the treatment of these conditions. Little data has been published regarding the placement of a TDR distal to a scoliosis fusion.

METHODS

Six thoracolumbar bovine spines (T12-S1) were instrumented from T12 to L5, with bilateral pedicle screw fixation at each level. L5-L6 and L6-S1 served as the test levels. One TDR (FlexiCore, Stryker Spine, Allendale, NJ) was initially performed adjacent to the fusion, followed by a subsequent TDR insertion at the last spinal segment. The applied load, total specimen deflection, and local transducer deflections were recorded before and after a TDR at both levels. The results were expressed as a percentage of the intact specimen. Flexion, extension, lateral bending, and torsional deflections were recorded.

RESULTS

There were no significant differences (P > 0.05) in sensor deflection observed at the L5-L6 and L6-S1 levels in the anterior and lateral transducers when compared to intact spines specimens. A similar effect was observed at the L5-L6 and L6-S1 levels in the anterior and lateral transducers when compared to intact or prior L5-L6 and intact L6-S1 constructs.

CONCLUSION

This study has shown that using the FlexiCore system at 1 and/or 2 intervertebral disc spaces caudal to a scoliosis fusion model did not significantly change the sensor deflection at the 2 segments adjacent to a scoliosis fusion construct. Future research will continue to define the clinical setting and patients best suited for management by TDR systems.

Evaluation of pelvic fixation in neuromuscular scoliosis: a retrospective study in 55 patients

The literature has described different indications for pelvic fixation in neuromuscular scoliosis. We retrospectively evaluated changes in pelvic obliquity for a minimum of two years among three groups: group I (initial pelvic obliquity >15 degrees; with pelvic fixation), group II (initial pelvic obliquity >15 degrees; without pelvic fixation), and group III (initial pelvic obliquity <15 degrees; without pelvic fixation). We used iliac screws for pelvic fixation in group I. There was significant postoperative improvement (p < 0.0001) in Cobb's angle and pelvic obliquity. There was no significant loss of correction in Cobb's angle, thoracic kyphosis, and lumbar lordosis among all three groups; however, group II showed significant correction loss in pelvic obliquity compared to groups I and III at final follow-up (p < 0.0001). Our results indicate that patients who have pelvic obliquity >15 degrees require pelvic fixation to maintain the correction and balance over time while obliquity <15 degrees does not require pelvic fixation.

LONG-SEGMENT SPINAL FIXATION USING PELVIC SCREWS

OBJECTIVE

Long spinal constructs that extend to the sacrum place added stress on sacral screws. To prevent premature loosening of sacral fixation in these cases, the addition of pelvic screw (iliac screw) fixation has gained in popularity. Pelvic screw fixation has also been used in cases where sacral screw fixation is not possible (e.g., in sacral tumors). Pelvic screw fixation is more straightforward than prior pelvic rod fixation techniques (e.g., the Galveston technique). We describe our technique for pelvic screw fixation and review our experience with this technique.

METHODS

Twenty consecutive patients who underwent spinal-pelvic fixation were followed over a 3-year period (2004–2007). The patient population consisted of 11 men and 9 women with an average age of 58.8 years. Indications for spinal-pelvic fixation in this series included kyphoscoliosis, lumbosacral pseudoarthrosis, sacral fractures, lumbosacral spondylolisthesis, sacral tumors, and lumbar osteomyelitic fractures. Radiographic outcomes were assessed using flexion-extension x-rays and computed tomographic scans. Clinical outcomes were assessed using Odom's criteria and modified Prolo scale.

RESULTS

One patient was lost to radiographic follow-up. One patient died after surgery. The mean follow-up for the remaining patients was 13 months (range, 1–21 mo). Odom's outcomes were rated as good to excellent in 11 (58%), fair in 7 (37%), and poor in 1 (5%) (one patient died). Preoperative and postoperative modified Prolo scores were 10.4 and 12.9, respectively (mean improvement, 2.5). Radiographic fusion across the lumbosacral junction was obtained in 16 (89%) of the 18 patients with follow-up. One patient required revision of a pelvic screw. There was one infection requiring explantation of hardware.

CONCLUSION

Pelvic screw fixation is a safe and effective technique that provides added structural support to S1 screws in long-segment spinal fusions. Furthermore, pelvic screw fixation provides a distal point of fixation in cases where sacral screw fixation is not possible. The use of polyaxial screws and connectors makes this technique easier than Galveston rod fixation of the pelvis.

Rate of complications in scoliosis surgery - a systematic review of the Pub Med literature

Background

Spinal fusion surgery is currently recommended when curve magnitude exceeds 40–45 degrees. Early attempts at spinal fusion surgery which were aimed to leave the patients with a mild residual deformity, failed to meet such expectations. These aims have since been revised to the more modest goals of preventing progression, restoring 'acceptability' of the clinical deformity and reducing curvature.

In view of the fact that there is no evidence that health related signs and symptoms of scoliosis can be altered by spinal fusion in the long-term, a clear medical indication for this treatment cannot be derived. Knowledge concerning the rate of complications of scoliosis surgery may enable us to establish a cost/benefit relation of this intervention and to improve the standard of the information and advice given to patients. It is also hoped that this study will help to answer questions in relation to the limiting choice between the risks of surgery and the "wait and see – observation only until surgery might be recommended", strategy widely used. The purpose of this review is to present the actual data available on the rate of complications in scoliosis surgery.

Materials and methods

Search strategy for identification of studies; Pub Med and the SOSORT scoliosis library, limited to English language and bibliographies of all reviewed articles. The search strategy included the terms; 'scoliosis'; 'rate of complications'; 'spine surgery'; 'scoliosis surgery'; 'spondylodesis'; 'spinal instrumentation' and 'spine fusion'.

Results

The electronic search carried out on the 1^st February 2008 with the key words "scoliosis", "surgery", "complications" revealed 2590 titles, which not necessarily attributed to our quest for the term "rate of complications". 287 titles were found when the term "rate of complications" was used as a key word. Rates of complication varied between 0 and 89% depending on the aetiology of the entity investigated. Long-term rates of complications have not yet been reported upon.

Conclusion

Scoliosis surgery has a varying but high rate of complications. A medical indication for this treatment cannot be established in view of the lack of evidence. The rate of complications may even be higher than reported. Long-term risks of scoliosis surgery have not yet been reported upon in research. Mandatory reporting for all spinal implants in a standardized way using a spreadsheet list of all recognised complications to reveal a 2-year, 5-year, 10-year and 20-year rate of complications should be established. Trials with untreated control groups in the field of scoliosis raise ethical issues, as the control group could be exposed to the risks of undergoing such surgery.

Complications in long fusions to the sacrum for adult scoliosis: minimum five-year analysis of fifty patients

STUDY DESIGN

A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis with fusion from T10 or higher to S1.

OBJECTIVES

To document the perioperative and long-term complications and instrumentation problems, and to attempt to determine variables which may influence these problems. It is not a study of curve correction, balance, or functional outcome.

SUMMARY OF BACKGROUND DATA

Several previous studies from this and other centers have shown a relatively high complication rate for this select group of patients. Various fusion techniques (anterior, posterior, autograft, allograft), various instrumentation techniques, and various immobilization techniques have created confusion as to the best methodology to employ. Minimal 2-year follow-ups have been standard, but longer follow-ups have shown additional problems.

METHODS

The study cohort consisted of 50 adult patients from a single center who had undergone corrective scoliosis surgery from T10 or higher to the sacrum and who had at least a 5-year minimum follow-up. The mean age was 54 years (range, 18-72), and the mean follow-up was 9.7 years (range, 5-26). All radiographs, office charts, and hospital charts were combed by an independent investigator for complications, which were divided into major and minor, as well as early, intermediate and late. The curvature values and corrections were the subject of a different article, and were not included in this study.

RESULTS

There were no deaths or spinal cord injuries. Six patients had nerve root complications, 4 of which totally recovered. Pseudarthrosis was seen in 24% of the patients, only 25% of which were detected within the 2-year follow-up period. Pseudarthrosis was most common at the lumbosacral level. There was no statistical difference in the pseudarthrosis rate between patients with sacral-only fixation versus iliac fixation. Painful implants requiring removal were noted in 11 of the 50 patients.

CONCLUSION

Long fusions to the sacrum in adults with scoliosis continue to have a high complication rate. As compared to the original publications in the 1980s (Kostuik and Hall, Spine 1983;8:489-500; Balderston et al, Spine 1986;11:824-9) the more recent articles have shown a reduction, but not elimination of the pseudarthrosis problem using segmental instrumentation and anterior fusion of the lumbar spine coupled with structural interbody grafting at L4-L5 and L5-S1. Two-year follow-up is inadequate as pseudarthrosis and painful implants often are detected later. Only 3 of the 12 patients with pseudarthrosis were detected within the first 2 years after surgery.

Impact of spine surgery on signs and symptoms of spinal deformity

Paediatric scoliosis is associated with signs and symptoms including reduced pulmonary function, increased pain and impaired quality of life, all of which worsen during adulthood, even when the curvature remains stable. Spinal fusion has been used as a treatment for nearly 100 years. In 1941, the American Orthopedic Association reported that for 70% of patients treated surgically, outcome was fair or poor: an average 65% curvature correction was reduced to 27% at >2 year follow-up and the torso deformity was unchanged or worse. Outcome was worse in children treated surgically before age 10, despite earlier intervention. Today, a reduced magnitude of curvature obtained by spinal fusion in adolescence can be maintained for decades. However, successful surgery still does not eliminate spinal curvature and it introduces irreversible complications whose long-term impact is poorly understood. For most patients there is little or no improvement in pulmonary function. Some report improved pain after surgery, some report no improvement and some report increased pain. The rib deformity is eliminated only by rib resection which can dramatically reduce respiratory function even in healthy adolescents. Outcome for pulmonary function and deformity is worse in patients treated surgically before the age of 10 years, despite earlier intervention. Research to develop effective non-surgical methods to prevent progression of mild, reversible spinal curvatures into complex, irreversible structural deformities, is long overdue.

Adolescent idiopathic scoliosis: natural history and long term treatment effects

Adolescent idiopathic scoliosis is a lifetime, probably systemic condition of unknown cause, resulting in a spinal curve or curves of ten degrees or more in about 2.5% of most populations. However, in only about 0.25% does the curve progress to the point that treatment is warranted.

Untreated, adolescent idiopathic scoliosis does not increase mortality rate, even though on rare occasions it can progress to the >100° range and cause premature death. The rate of shortness of breath is not increased, although patients with 50° curves at maturity or 80° curves during adulthood are at increased risk of developing shortness of breath. Compared to non-scoliotic controls, most patients with untreated adolescent idiopathic scoliosis function at or near normal levels. They do have increased pain prevalence and may or may not have increased pain severity. Self-image is often decreased. Mental health is usually not affected. Social function, including marriage and childbearing may be affected, but only at the threshold of relatively larger curves.

Non-operative treatment consists of bracing for curves of 25° to 35° or 40° in patients with one to two years or more of growth remaining. Curve progression of ≥ 6° is 20 to 40% more likely with observation than with bracing. Operative treatment consists of instrumentation and arthrodesis to realign and stabilize the most affected portion of the spine. Lasting curve improvement of approximately 40% is usually achieved.

In the most completely studied series to date, at 20 to 28 years follow-up both braced and operated patients had similar, significant, and clinically meaningful reduced function and increased pain compared to non-scoliotic controls. However, their function and pain scores were much closer to normal than patient groups with other, more serious conditions.

Risks associated with treatment include temporary decrease in self-image in braced patients. Operated patients face the usual risks of major surgery, a 6 to 29% chance of requiring re-operation, and the remote possibility of developing a pain management problem.

Knowledge of adolescent idiopathic scoliosis natural history and long-term treatment effects is and will always remain somewhat incomplete. However, enough is know to provide patients and parents the information needed to make informed decisions about management options.

[Complications of surgical treatment of spinal deformities: a prospective multicentric study of 3311 patients]

PURPOSE OF THE STUDY

The incidence of complications secondary to surgical treatment of spinal deformations remains imprecise. The purpose of this prospective multicentric observational study was to assess the incidence of intra- and postoperative complications secondary to this type of surgery to detail the observed complications and to identify favoring factors.

MATERIAL AND METHODS

For this study, we included 3311 patients who underwent surgery during a 12-month period for spinal deformation, defined as idiopathic or secondary scoliosis or kyphosis, irrespective of the localization, severity, or type of surgery performed. Four main categories of complications were studied: general, infectious, neurological, and mechanical. Pre- and intraoperative variables recorded were: epidemiological and morphological data, history of surgery for the same spinal deformation, comorbid conditions, type of deformation treated (nature, anatomic localization, severity, reducibility), type of surgery performed (approach, duration of the operation), operative blood loss, extent and localization of the fusion, associated neurological release, vertebral osteotomy or not, type of graft used. Two types of analysis were performed. The first was a descriptive analysis to detail the overall incidence of complications and the incidence of each of the four main categories. The second was a multivariate analysis designed to determine factors significantly associated with complication occurrence.

RESULTS

Mean age of the cohort was 27 +/- 18 years; 6.8% of the patients had had a prior operation for the spinal deformation. The deformation was scoliosis in 90% (mean angle 56 +/- 20 degrees) and kyphosis in 10% (mean angle 47 +/- 23 degrees). An isolated posterior approach was used for 72.5% of patients, an isolated anterior approach for 6.4%, and a combined anteroposterior approach for 21.1%. Seven hundred four patients (21.3%) had one or more complications (850 complications) during or shortly after their operation. The incidences of general, infectious, mechanical and neurological complications were: 5.7%, 4.7%, 11.5%, and 1.8% respectively. Globally, considering all types of complications, the following factors were found to be significantly associated with complication occurrence: patient age, ASA score, extent of the fusion, presence of vertebral osteotomy, inclusion of the sacrum in the arthrodesis, and initial angle of the treated deformation. For patients with scoliosis, the following factors were significantly associated with a secondary central neurological disorder: initial angle of the deformation, use of vertebral osteotomy, type of curvature with greater risk for thoracic curvatures and double thoracic and lumbar curvatures.

CONCLUSION

This work enabled us to determine the overall rate of complications after surgical treatment of spinal deformations. Certain risk factors related with complication occurrence were identified, but the heterogeneous nature of the population and the methodology used to identify these factors only allowed detection of trends. A future study by etiological group or focusing on specific complications should allow a more precise analysis of these risk factors. This overall rate of complications should be used to better inform patients and their family about the risks of this type of surgery.

Impairment of perineal care functions after long fusions of the lumbar spine

The purpose of this study was to investigate the incidence of perineal care impairment after extended thoracolumbar and thoracolumbosacral spinal fusions. Fourteen adult patients with fusions from the thoracic spine to L5 or the sacrum completed a questionnaire regarding their ability to do perineal care. The mean number of vertebral levels fused was 9.5 (range, 6-16 levels) with five patients having spinal fusion to L5 and nine having fusion to the sacrum. Thirty-six percent (five of 14 patients) reported difficulty doing perineal care after fusion. Maintenance of L5-S1 segmental motion did not seem to reduce occurrence of perineal care problems. We think that extended thoracolumbar fusion and thoracolumbosacral fusion can produce postoperative difficulty in doing perineal care.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Blood loss in adult spinal surgery

Spinal surgery in adults can vary from simple to complex and can also have variable anticipated surgical blood loss. There are several factors that can put patients at increased risk for greater intraoperative blood loss. These factors, including a review of the literature, will be discussed.

Degenerative scoliosis. Options for surgical management

Adult degenerative scoliosis patients present a challenge in trying to achieve the greatest benefit with the least amount of intervention. Tailoring the treatment to the severity of the symptoms and the deformity appears to be vital. Full understanding of the deformity in the coronal and sagittal planes as well as the neural impingement can guide one to the appropriate intervention. The first operation is critical in providing the best prognosis for the long term. Decompression alone is performed in patients with small magnitudes of scoliosis and minimal lateral listhesis. Decompression and posterior fusion with instrumentation is performed on patients with moderate deformity and lateral listhesis, but a balanced sagittal plane. The more technically challenging and larger operation, a combined anterior and posterior fusion with instrumentation, is reserved for those patients with not only moderate to severe curves, but also coronal and sagittal imbalance. Performing a smaller operation on these patients may not only be short-lived but may also start a series of higher-risk revisions. There is a distinct lack of studies identifying and documenting the risks, morbidity, and reoperation rates in this patient population as compared with other deformity groups. Treatment of degenerative scoliosis patients presents a challenge that is only growing larger in numbers with the aging population.

Biomechanical comparison of lumbosacral fixation techniques in a calf spine model

STUDY DESIGN

biomechanical testing of the strength and stability of lumbosacral fixation constructs.

OBJECTIVES

The purpose of this study was to quantify and compare the biomechanical properties of five different lumbosacral fixation constructs and determine the benefit of adding supplementary fixation to S1 screws.

SUMMARY OF BACKGROUND DATA

Extension of long fusions to the sacrum remains a difficult clinical challenge. Only a limited number of biomechanical studies have evaluated the different fixation methods available, and none has included both nondestructive and load to failure testing of these fixation methods.

METHODS

Six fresh-frozen calf spines were prepared and tested for each construct. The five constructs tested included the following: S1 screws alone, S1 screws and S2 proximally directed screws, S1 screws and S2 distally directed screws, S1 screws and intrasacral rods, and S1 screws and iliac screws. Nondestructive, multidirectional flexibility analyses included four loading methods followed by a destructive flexural load to failure. Lumbosacral peak range of motion (millimeters or degrees) and ultimate failure load (Nm) of the five reconstruction techniques were statistically compared using a one-way analysis of variance combined with a Student-Newman-Keuls post hoc test.

RESULTS

S1 screw strain tested in flexion-extension was significantly reduced by the addition of any second point of distal fixation. There was no significant difference between any of the different sacral fixation constructs (P > 0.05). In axial compression, only the addition of iliac screws significantly reduced S1 screw strain. In destructive testing under flexion loading, only iliac screws statistically increased the load at failure (P = 0.005).

CONCLUSION

This study demonstrates the effectiveness of adding a second fixation point distal to the S1 screws in reducing S1 screw strain. Iliac fixation is more effective than secondary sacral fixation points but may not be necessary in all clinical situations. Only iliac fixation effectively increased the load to failure under catastrophic loading conditions. Supplementary sacral fixation failed to significantly protect against catastrophic failure. These findings support the clinical observation that iliac fixation is least likely to fail in high-risk, long fusions. Whether testing range of motion, screw strain, or load to failure, no benefit could be demonstrated for intrasacral rod placement when compared with other supplementary sacral fixation techniques. Intrasacral rod placement was equal to a second sacral screw in reducing S1 screw strain during flexion-extension loading. It was not as effective as iliac fixation in reducing screw strain or preventing catastrophic failure. When choosing fixation methods in long fusions to the sacrum, this study supports the use of iliac fixation as the method least likely to loosen or pull out. A second point of sacral fixation also offers biomechanical advantages when compared with S1 fixation alone and may be an appropriate choice in less "high risk" fusions to the sacrum.